Perhaps two appointments for the Supreme Court for Trump's second term, if Thomas and Alito decide to hang it up.
Think Sotomayor and Kagan will try to stick around and attempt to outlive RBG. Don't think there will be a big swing in the lib/conservative balance unless there is an unexpected health issue, or someone gets foul of ethics and is likely to get impeached. Hopefully, Thomas and Alito will think about retirement sometime during the next four years, so Trump can make certain the conservative majority is safe for at least 20-30 years.